Polycrystal plasticity modeling of intracrystalline boundary textures

A finite element formulation is used to simulate and study the deformation response of face-centered cubic polycrystals. The polycrystals consist of rhombic dodecahedral-shaped crystals, each finely discretized with tetrahedral elements. Rhombic dodecahedra are twelve-sided, regular, space-filling polyhedra that are used to represent a microstructure with equiaxed grains. Material behavior is based on rate-dependent, crystallographic slip on a restricted number of slip systems. The numerical formulation maintains compatibility and equilibrium under the application of applied loads using an assumed-stress hybrid finite element methodology. Spatial variations in deformation arise in the polycrystal even under simple external loadings and lead to grain subdivision characterized by the formation of;boundaries separating regions with differing lattice orientation. Particular attention is focused on the resulting crystallographic misorientation across these boundaries and their orientations relative to the applied loads. This evolving intragrain boundary texture is compared to published experimental data obtained using TEM and Kikuchi pattern analysis. (C) 1999 Acta Metallurgica Inc. Published by Elsevier Science Ltd All rights reserved.